Semiconductor device

ABSTRACT

In a multi-core semiconductor device, a data bus between CPUs or the like consumes a larger amount of power. By provision of a plurality of CPUs which transmit data by a backscattering method of a wireless signal, a router circuit which mediates data transmission and reception between the CPUs or the like, and a thread control circuit which has a thread scheduling function, a semiconductor device which consumes less power and has high arithmetic performance can be provided at low cost.

TECHNICAL FIELD

The present invention relates to a semiconductor device having aplurality of CPUs, which is called a multi-core semiconductor device.

BACKGROUND ART

Currently, almost all central processing units (CPUs) included insemiconductor devices adopt an architecture called a stored-programsystem. In this stored-program system, instructions to be processed by aCPU and data necessary for the processing are stored in a memory, andthe CPU performs processing by sequentially reading data from thememory. Therefore, for the semiconductor device having a CPU, techniquesfor increasing an operating frequency of CPU and increasing a memoryaccess rate are employed in order to improve performance.

The semiconductor device can have higher arithmetic processingperformance by increasing the operating frequency of the CPU. However,the amount of electric power consumed by the semiconductor device isincreased in proportion to the operating frequency. In addition, anincrease in operating frequency generally requires an increase incircuit size of the CPU. Thus, the CPU consumes more power as theoperating frequency is increased. Therefore, there has been proposed asystem for improving overall processing performance of a semiconductordevice by providing a plurality of CPUs which consume less power due tosuppressed circuit size and operating frequency and by distributingprocesses to all of the CPUs (for example, Reference 1: JapanesePublished Patent Application No. 2006-268070). Such a system may bereferred to as a multi-core system.

As the multi-core system, various structures and data processing methodshave been proposed, such as a symmetric multiprocessing (SMP) systemwhere CPUs are treated equally, an asymmetric multiprocessing (AMP)system where CPUs are treated unequally, a single instruction multipledata (SIMD) method in which plural pieces of data are processed with asingle instruction, and a multiple instruction multiple data (MIMD)method in which plural pieces of data are processed with pluralinstructions. The multi-core system can reduce power consumption of eachCPU.

DISCLOSURE OF INVENTION

However, even if the multi-core system is employed, since datatransmission and reception between CPUs or the like become necessary, anincrease in the amount of power consumed by a data bus for them becomesa problem.

In view of the above problem, it is an object of the present inventionto provide a semiconductor device which is prevented from consuming morepower even if it has a plurality of CPUs.

A semiconductor device of the present invention includes a plurality ofCPUs, a router circuit, and a thread control circuit. Each CPU functionsto transmit and receive data to and from the router circuit with awireless signal. The router circuit functions to transmit and receivedata to and from each CPU with a wireless signal. The thread controlcircuit has a function to allocate an instruction to be executed by eachCPU, i.e., a scheduling function.

Data transmission from each CPU to the router circuit is carried outthrough modulation of a wireless signal. Modulation such as phasemodulation or amplitude modulation is achieved by turning on or off aswitch of a wireless circuit included in each CPU. With the use of sucha modulation method, i.e., a backscattering method, the amount of powerneeded for data transmission from each CPU can be reduced.

A feature of the semiconductor device of the present invention disclosedin this specification is to include a plurality of CPUs, a routercircuit, a thread control circuit connected to the router circuitthrough a first bus, and an external device controller connected to therouter circuit through a second bus. Each of the plurality of CPUsincludes a first wireless circuit which includes a first antennacircuit, a first demodulation circuit, and a first modulation circuitand a CPU core which includes a control circuit, an arithmetic circuit,a cache memory, and a general purpose register. The router circuitincludes a data processing circuit and a second wireless circuit whichincludes a second antenna circuit, a second demodulation circuit, and asecond modulation circuit. The first wireless circuit and the secondwireless circuit each function to transmit and receive data between theCPU and the router circuit with a wireless signal. The first wirelesscircuit functions to transmit data to the second wireless circuit by abackscattering method. The data processing circuit functions to processand store first data to be transmitted to or received from each of theplurality of CPUs, second data to be transmitted to or received from thethread control circuit, and third data to be transmitted to or receivedfrom the external device controller. The thread control circuitfunctions to appropriately allocate an instruction to be executed by theCPU core to the CPU core. The external device controller functions totransmit and receive data to and from an external device which isconnected through an external data input line and an external dataoutput line.

Another feature of the semiconductor device of the present inventiondisclosed in this specification is to include a plurality of CPUs, arouter circuit, a thread control circuit connected to the router circuitthrough a first bus, and an external device controller connected to therouter circuit through a second bus. Each of the plurality of CPUsincludes a first wireless circuit which includes a first antennacircuit, a first demodulation circuit, a first modulation circuit, and apower supply circuit and a CPU core which includes a control circuit, anarithmetic circuit, a cache memory, and a general purpose register. Thepower supply circuit functions to generate a power supply voltage to besupplied to the CPU from a wireless signal received by the first antennacircuit. The router circuit includes a data processing circuit and asecond wireless circuit which includes a second antenna circuit, asecond demodulation circuit, and a second modulation circuit. The firstwireless circuit and the second wireless circuit function to transmitand receive data between the CPU and the router circuit with a wirelesssignal. The first wireless circuit functions to transmit data to thesecond wireless circuit by a backscattering method. The data processingcircuit functions to process and store first data to be transmitted toor received from each of the plurality of CPUs, second data to betransmitted to or received from the thread control circuit, and thirddata to be transmitted to or received from the external devicecontroller. The thread control circuit functions to appropriatelyallocate an instruction to be executed by the CPU core to the CPU core.The external device controller functions to transmit and receive data toand from an external device which is connected through an external datainput line and an external data output line.

Another feature of the semiconductor device of the present inventiondisclosed in this specification is to include a plurality of CPUs, arouter circuit, a thread control circuit connected to the router circuitthrough a first bus, and an external device controller connected to therouter circuit through a second bus. Each of the plurality of CPUsincludes a first wireless circuit which includes a first antennacircuit, a third antenna circuit, a first demodulation circuit, a firstmodulation circuit, a first power supply circuit, and a second powersupply circuit and a CPU core which includes a control circuit, anarithmetic circuit, a cache memory, and a general purpose register. Thefirst power supply circuit functions to generate a power supply voltageto be supplied to the CPU from a first wireless signal received by thefirst antenna circuit. The second power supply circuit includes astep-up circuit and functions to generate a power supply voltage to besupplied to the CPU from a second wireless signal received by the thirdantenna circuit. The router circuit includes a data processing circuitand a second wireless circuit which includes a second antenna circuit, asecond demodulation circuit, and a second modulation circuit. The firstwireless circuit and the second wireless circuit function to transmitand receive data between the CPU and the router circuit with a wirelesssignal. The first wireless circuit functions to transmit data to thesecond wireless circuit by a backscattering method. The data processingcircuit functions to process and store first data to be transmitted toor received from each of the plurality of CPUs, second data to betransmitted to or received from the thread control circuit, and thirddata to be transmitted to or received from the external devicecontroller. The thread control circuit functions to appropriatelyallocate an instruction to be executed by the CPU core to the CPU core.The external device controller functions to transmit and receive data toand from an external device which is connected through an external datainput line and an external data output line.

In the semiconductor device of the present invention having the abovestructure, the external device controller can be a DRAM controller, aPCI bus controller, or a USB controller.

Each CPU may be formed using a thin film transistor which includes as anactive layer a semiconductor thin film formed over a substrate having aninsulating surface. Note that the substrate having an insulating surfaceis preferably one of a glass substrate, a plastic substrate, and asilicon-on-insulator (SOI) substrate.

The present invention can provide a multi-core semiconductor devicewhich consumes less power and has high arithmetic performance, at lowcost. By providing a plurality of CPUs, a router circuit, and a threadcontrol circuit and employing a backscattering method for datatransmission from each CPU to the router circuit, the present inventioncan also provide a semiconductor device which can transmit data fromeach CPU to the router circuit while consuming a very small amount ofpower. The present invention can further provide a semiconductor devicehaving a lot of flexibility in physical form because the CPU does notneed to be electrically connected to another CPU, the router circuit,the thread control circuit, and an external terminal.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a semiconductor device of the presentinvention.

FIG. 2 is a block diagram of a CPU included in a semiconductor device ofthe present invention.

FIG. 3 is a block diagram of a router circuit included in asemiconductor device of the present invention.

FIG. 4 shows a structure of a wireless circuit of a CPU included in asemiconductor device of the present invention.

FIG. 5 shows a structure of a wireless circuit of a CPU included in asemiconductor device of the present invention.

FIGS. 6A to 6D show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 7A to 7C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 8A and 8B show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 9A and 9B show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 10A and 10B show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 11A to 11C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 12A to 12C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 13A and 13B show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 14A to 14C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 15A to 15C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 16A to 16C show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 17A and 17B show an example of a method for manufacturing asemiconductor device of the present invention.

FIGS. 18A to 18H show examples of applications of a semiconductor deviceof the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment modes of the present invention will be hereinafter describedwith reference to the accompanying drawings. However, the presentinvention can be carried out in many different modes, and it is easilyunderstood by those skilled in the art that the mode and detail of thepresent invention can be modified in various ways without departing fromits spirit and scope. Therefore, the present invention is notinterpreted as being limited to the description in the embodiment modes.Note that in the drawings illustrating the embodiment modes, the sameportions or portions having a similar function are denoted by the samereference numerals, and repetitive explanation thereof is omitted.

(Embodiment Mode 1)

Embodiment Mode 1 describes an example of a structure of a semiconductordevice of the present invention with reference to FIGS. 1 to 3. FIGS. 1to 3 are block diagrams of a semiconductor device, a CPU, and a routercircuit of this embodiment mode, respectively.

In FIG. 1, a semiconductor device 100 has first to fourth CPUs 101 to104, a router circuit 105, a thread control circuit 106, and an externaldevice controller 107. The first to fourth CPUs 101 to 104 have first tofourth CPU cores 108 to 111 and first to fourth wireless circuits 112 to115, respectively. Note that in FIG. 1, the router circuit 105 transmitsfirst to fourth wireless transmission signals 118 to 121 to the first tofourth CPUs 101 to 104, and the first to fourth CPUs 101 to 104 transmitfifth to eighth wireless transmission signals 122 to 125 to the routercircuit 105, respectively. The semiconductor device 100 transmits andreceives a data signal or a control signal to and from an externaldevice connected to the semiconductor device 100 with the use of anexternal data output line 116 and an external data input line 117.

Next, a specific structure of CPU is described with reference to FIG. 2.Note that in FIG. 2, a CPU 200 corresponds to each of the first tofourth CPUs 101 to 104 of FIG. 1; a CPU core 201 corresponds to each ofthe first to fourth CPU cores 108 to 111 of

FIG. 1; and a wireless circuit 202 corresponds to each of the first tofourth wireless circuits 112 to 115 of FIG. 1.

The CPU core 201 has a control circuit 203, an arithmetic circuit 204, acache memory 205, and a general purpose register 206. The controlcircuit 203 controls the processing in the CPU 200. The arithmeticcircuit 204 performs numerical operation and logical operation. Thecache memory 205 is a storage device which stores programs processed bythe CPU 200 and data necessary for the processing. The general purposeregister 206 is used as a storage source of data which are used fornumerical operation and logical operation and as a storage destinationof operation results. Note that the CPU core 201 can employ anarchitecture such as a reduced instruction set computer (RISC) or acomplex instruction set computer (CISC).

The wireless circuit 202 has an antenna circuit 207, a demodulationcircuit 208, a modulation circuit 209, and a power supply circuit 210.The antenna circuit 207 functions to transmit and receive acommunication signal. For example, the antenna circuit 207 may beprovided with a coil in the case of employing an electromagneticinduction method, or may be provided with a dipole antenna in the caseof employing an electric field method. The demodulation circuit 208functions to extract reception data from a communication signal. Forexample, the demodulation circuit 208 may be a low-pass filter (LPF).The modulation circuit 209 functions to superimpose transmission data ona communication signal. The power supply circuit 210 functions togenerate a power supply voltage for the CPU 200 from a communicationsignal. For example, the power supply circuit 210 can be formed using arectifier circuit and a storage capacitor. Although this embodiment modedescribes a so-called passive CPU which generates a power supply voltagefrom a wireless signal received, a so-called active CPU which supplies apower supply voltage from an incorporated battery can also be used.Alternatively, a structure in which a power supply voltage is suppliedfrom a commercial power supply can also be used.

Note that the data transmission from the first to fourth CPUs 101 to 104to the router circuit 105 is conducted using a modulation method byturning on or off a switch of the modulation circuit, i.e., abackscattering method. As the backscattering method, a phase modulationmethod or an amplitude modulation method can be used. As a data encodingmethod, a technique such as a quadrature phase shift keying (QPSK)method, a binary phase shift keying (BPSK) method, or an 8 phase shiftkeying (8PSK) method can be used. These modulation methods do notrequire CPUs themselves to transmit a transmission signal; therefore,these methods can reduce power necessary for the data transmission fromthe CPUs. Thus, employment of a backscattering method for datatransmission from a CPU to reduce power consumption is a feature of thesemiconductor device of the present invention.

Here, each of the QPSK method, the BPSK method, and the 8PSK method is amodulation method for converting digital values into analog signals andis a phase shift keying method for expressing information using acombination of a plurality of waves with phase shifts. With the QPSKmethod, four-value (2-bit) information can be transmitted or received ata time by using a total of four waves, a reference sine wave and waveswith phase shifts of 90°, 180°, and 270°, and by allocating differentvalues to each of them. With the BPSK method, two-value (1-bit)information can be transmitted or received at a time by using areference sine wave and a wave with an inverted phase and by relatingone of them to 0 and the other to 1. With the 8PSK method, eight-value(3-bit) information can be transmitted or received at a time by using atotal of eight waves, a reference sine wave and waves with phase shiftsof 45° each and by allocating different values to each of them.

Next, a specific structure of the router circuit is described withreference to FIG. 3. In FIG. 3, a router circuit 300 corresponding tothe router circuit 105 of FIG. 1 has an antenna circuit 301, ademodulation circuit 302, a modulation circuit 303, a first buscontroller circuit 304, a second bus controller circuit 305, and a dataprocessing circuit 306. The antenna circuit 301, the demodulationcircuit 302, and the modulation circuit 303 are collectively referred toas a wireless circuit 309. The antenna circuit 301 functions to transmitand receive a communication signal to and from the CPUs. For example,the antenna circuit 301 may be provided with a coil in the case ofemploying an electromagnetic induction method, or may be provided with adipole antenna in the case of employing an electric field method. Thedemodulation circuit 302 functions to extract reception data from acommunication signal. For example, the demodulation circuit 302 may bean LPF. The modulation circuit 303 functions to superimpose transmissiondata on a communication signal. The first bus controller circuit 304 isconnected to the thread control circuit 106 of FIG. 1 through a firstbus 307 and functions to control data transmission and reception to andfrom the thread control circuit 106. The second bus controller circuit305 is connected to the external device controller 107 of FIG. 1 througha second bus 308 and functions to control data transmission andreception to and from the external device controller 107.

The data processing circuit 306 functions to process and store receptiondata from the CPUs, transmission data to the. CPUs, data input andoutput through the first bus 307, and data input and output through thesecond bus 308, and functions to manage and conduct data transmissionand reception between the CPUs, between the CPUs and the thread controlcircuit, and between the CPUs and the external device controller.

As described above, the router circuit 105 can function to mediate datatransmission and reception between the first to fourth CPUs 101 to 104and the thread control circuit 106 or the external device controller107. For example, when the router circuit 105 receives, from the firstCPU 101, transmission data to which the external device controller 107is designated as a data transmission destination, the router circuit 105transmits the data to the transmission destination, i.e., the externaldevice controller 107. By employing such a method as described above bywhich data transmission and reception are mediated by the router circuit105, there is an advantage that conflict in data transmission andreception between the CPUs, between the CPUs and the thread controllercircuit, and between the CPUs and the external device controller hardlyoccurs even if a plurality of CPUs are provided. In addition, datatransmission and reception can be efficiently allocated to the CPU, thethread control circuit, or the external device controller which requiresdata transmission and reception.

Note that a wireless signal is used for data transmission from therouter circuit 105 to the first to fourth CPUs 101 to 104, and atechnique such as a time division multiple access (TDMA) method or acode division multiple access (CDMA) method can be employed. Datatransmission and reception between the router circuit 105 and the threadcontrol circuit 106 or the external device controller 107 can beconducted using a wireless signal or a wired signal.

Here, the TDMA method is a method in which a single frequency is sharedby a plurality of transmitters in turn at short intervals. The CMDAmethod is a method by which transmission data of a plurality oftransmitters are each multiplied by different codes and all transmissiondata are synthesized and transmitted using a single frequency. Areceiver can extract only transmission data of a relevant transmitter bymultiplying the synthesized signal with the code of the relevanttransmitter.

The thread control circuit 106 functions to allocate processing (athread) to be executed by a CPU to the CPU. Specifically, the threadcontrol circuit 106 functions to schedule threads with the use ofinformation showing an operation state such as being running or idle,information showing running and idle threads, and information about theorder of thread priorities, with respect to the first to fourth CPUs 101to 104 in the semiconductor device 100. In addition, the thread controlcircuit 106 functions to allocate information about a CPU assigned tohandle processing and data necessary for the processing to a thread toproduce thread information and functions to transmit the threadinformation to the router circuit 105. Note that the thread informationis transmitted to the relevant CPU of the first to fourth CPUs 101 to104 through the router circuit 105 and executed appropriately.

Note that a thread is a unit of processing of a CPU. A normal CPUemploys a processing method called multitasking. In this method, aplurality of processes are pseudo-simultaneously executed by temporallychanging processes. However, changing processes may require a changingoperation with heavy load such as data storing or reading of an internalregister of a CPU. A thread is a process which is divided so that achanging process is not needed. In other words, the division ofprocessing into threads enables efficient multitasking.

The external device controller 107 functions to transmit and receive adata signal or a control signal between the semiconductor device 100 andan external device connected to the semiconductor device 100, with theuse of the external data output line 116 and the external data inputline 117. For example, when the semiconductor device 100 is connected toan external dynamic random access memory (DRAM), the external devicecontroller 107 functions as a DRAM controller. When the semiconductordevice 100 is connected to an external peripheral device having a PCIbus, the external device controller 107 functions as a PCI buscontroller. When the semiconductor device 100 is connected to anexternal universal serial bus (USB), the external device controller 107functions as a USB controller. In addition, the external devicecontroller 107 functions to transmit and receive data to and from therouter circuit 105.

In the operation of the semiconductor device 100, for example, if thefirst CPU 101 executes an instruction to generate a new thread, thefirst CPU 101 transmits an instruction requiring generation of a threadto the thread control circuit 106 through the router circuit 105. Thethread control circuit 106 determines a CPU, to which the thread is tobe allocated, from idle CPUs or CPUs executing threads with lowpriority, and transmits thread information including an address of aninstruction to be executed to the CPU through the router circuit. Thus,the thread control circuit 106 has a function to allocate a thread to arelevant CPU, i.e., a scheduling function.

In a semiconductor device with a normal multiprocessor structure,allocation of a thread to a relevant CPU is carried out by software withthe use of a thread scheduling function of an operating system (OS)corresponding to a multiprocessor. However, the scheduling functionitself is achieved by a thread; therefore, a CPU is used. Thus,operation performance of the semiconductor device as a whole is lowered.

On the other hand, the semiconductor device of the present invention canrealize thread scheduling without lowering the arithmetic processingperformance of a CPU by provision of a thread control circuit having athread scheduling function. Thus, the semiconductor device of thepresent invention can realize thread scheduling without lowering theoperation performance of a CPU.

As described above, by provision of a plurality of CPUs which use abackscattering method of a wireless signal for data transmission, arouter circuit which mediates data transmission and reception betweenCPUs or the like, and a thread control circuit which has a threadscheduling function, a semiconductor device which consumes less powerand has high arithmetic performance can be provided at low cost.

(Embodiment Mode 2)

Embodiment Mode 2 describes the structure of the wireless circuit of theCPU in the above embodiment mode with reference to FIG. 4. FIG. 4 showsa case where the wireless circuit has the antenna circuit 207, thedemodulation circuit 208, the modulation circuit 209, and the powersupply circuit 210.

In FIG. 4, the modulation circuit 209 has a transistor 406 and cansuperimpose transmission data on a communication signal by changing thepotential of a modulation signal line 402.

The demodulation circuit 208 has a first coupling capacitor 407, a firstdiode 408, a second diode 409, an LPF resistor 410, and an LPF capacitor411. A first AC voltage obtained from a communication signal by theantenna circuit 207 is supplied through a wiring 401 and converted intoa second AC voltage by the first coupling capacitor 407, and the secondAC voltage is supplied to a wiring 412. The second AC voltage isconverted into a DC voltage by a rectifier circuit which has the firstdiode 408 and the second diode 409, and the DC voltage is supplied to awiring 413. The DC voltage is converted into a demodulated signal by anLPF which has the LPF resistor 410 and the LPF capacitor 411, and thedemodulated signal is supplied to a demodulation signal line 403.

The power supply circuit 210 has a second coupling capacitor 414, athird diode 415, a fourth diode 416, and a storage capacitor 417. Thefirst AC voltage obtained from a communication signal by the antennacircuit 207 is supplied through the wiring 401 and converted into athird AC voltage by the second coupling capacitor 414, and the third ACvoltage is supplied to a wiring 418. The third AC voltage is convertedinto a power supply signal by a rectifier circuit which has the thirddiode 415 and the fourth diode 416, and the power supply signal issupplied to a power supply wiring 404. The power supply signal issmoothed by the storage capacitor 417. Note that a ground signal issupplied through a ground wiring 405.

As described above, by provision of a wireless circuit which enableswireless data transmission and reception in a CPU and by performing datatransmission and reception between CPUs or the like with the use of abackscattering method of a wireless signal through a router, asemiconductor device which consumes less power and has high arithmeticperformance can be provided at low cost.

Note that this embodiment mode can be combined with any of structures ofsemiconductor devices described in the other embodiment modes of thisspecification.

(Embodiment Mode 3)

Embodiment Mode 3 describes a structure of a wireless circuit of a CPU,which is different from that of Embodiment Mode 2, with reference toFIG. 5.

In FIG. 5, the antenna circuit 207 has a first antenna 534 and a secondantenna 535. The first antenna 534 is used for data transmission andreception with a first communication signal and for generation of afirst power supply voltage from the first communication signal. Thesecond antenna 535 is used for generation of a second power supplyvoltage from a second communication signal.

The modulation circuit 209 has a transistor 506 and can superimposetransmission data on the first communication signal by changing thepotential of a modulation signal line 502.

The demodulation circuit 208 has a first coupling capacitor 507, a firstdiode 508, a second diode 509, an LPF resistor 510, and an LPF capacitor511. A first AC voltage obtained from the first communication signal bythe first antenna 534 is supplied through a wiring 501 and convertedinto a second AC voltage by the first coupling capacitor 507, and thesecond AC voltage is supplied to a wiring 512. The second AC voltage isconverted into a first DC voltage by a rectifier circuit which has thefirst diode 508 and the second diode 509, and the first DC voltage issupplied to a wiring 513. The first DC voltage is converted into ademodulated signal by an LPF which has the LPF resistor 510 and the LPFcapacitor 511, and the demodulated signal is supplied to a demodulationsignal line 503.

The power supply circuit 210 has a first power supply circuit 536 and asecond power supply circuit 537. The first power supply circuit 536 hasa second coupling capacitor 514, a third diode 515, a fourth diode 516,and a first storage capacitor 517. The first AC voltage obtained fromthe first communication signal by the first antenna 534 is suppliedthrough the wiring 501 and converted into a third AC voltage by thesecond coupling capacitor 514, and the third AC voltage is supplied to awiring 518. The third AC voltage is converted into a first power supplysignal by a rectifier circuit which has the third diode 515 and thefourth diode 516, and the first power supply signal is supplied to afirst power supply wiring 539. The first power supply signal is smoothedby the first storage capacitor 517.

The second power supply circuit 537 has a third coupling capacitor 519,a fourth coupling capacitor 520, fifth to eighth diodes 521 to 524, asecond storage capacitor 525, and a third storage capacitor 526. Afourth AC voltage obtained from the second communication signal by thesecond antenna 535 is supplied through a wiring 538 and converted into afifth AC voltage by the third coupling capacitor 519, and the fifth ACvoltage is supplied to a wiring 527. The fifth AC voltage is convertedinto a second DC voltage by a rectifier circuit which has the fifthdiode 521 and the sixth diode 522, and the second DC voltage is suppliedto a wiring 528. The second DC voltage is smoothed by the second storagecapacitor 525.

In addition, the fifth AC voltage is converted into a sixth AC voltageby the fourth coupling capacitor 520, and the sixth AC voltage issupplied to a wiring 529. The sixth AC voltage is converted into a thirdDC voltage by a rectifier circuit which has the seventh diode 523 andthe eighth diode 524, and the third DC voltage is supplied to a secondpower supply wiring 530 as a second power supply signal. The secondpower supply signal is smoothed by the third storage capacitor 526. Notethat the second power supply signal is increased to a high potentialwhen added to a potential accumulated in the second storage capacitor525.

With a ninth diode 531 and a tenth diode 532, a power supply signal witha higher potential of the first power supply signal and the second powersupply signal is supplied to a power supply wiring 504 as a power supplyvoltage. Note that the power supply voltage is smoothed by a fourthstorage capacitor 533. Note also that a ground signal is suppliedthrough a ground wiring 505. The fourth storage capacitor 533 can be acapacitor such as an electric double layer capacitor. Instead of acapacitor, the fourth storage capacitor 533 may be a secondary batterysuch as a lithium battery, preferably a lithium polymer battery using agel electrolyte, or a lithium-ion battery.

Here, the second power supply circuit 537 is a step-up circuit. Thus, itis possible to supply a power supply voltage sufficient for operating aCPU even when the second communication signal is weak. In other words,continuous supply of weak second communication signal enables a CPU tocontinue its operation even if the first communication signal issupplied only when the CPU conducts wireless communication and the firstcommunication signal is stopped from being supplied when the CPU doesnot conduct wireless communication. Accordingly, wireless communicationwith a CPU can be achieved with less power consumption.

As described above, by provision, in a CPU, of a wireless circuitenabling wireless data transmission and reception and a step-up circuitgenerating a certain power even if it receives a weak signal and byperforming data transmission and reception between CPUs or the like withthe use of a backscattering method of a wireless signal through arouter, a semiconductor device which consumes less power and has higharithmetic performance can be provided at low cost.

Note that this embodiment mode can be combined with any of structures ofthe semiconductor devices described in the other embodiment modes ofthis specification.

(Embodiment Mode 4)

Embodiment Mode 4 describes an example of a method for manufacturing thesemiconductor device described in the above embodiment modes withreference to drawings. This embodiment mode describes a structure inwhich an antenna circuit and a power supply circuit in a CPU of thesemiconductor device are formed using thin film transistors over thesame substrate. It is to be noted that when an antenna circuit and apower supply circuit are formed at a time over the same substrate,reduction in size of the semiconductor device can be achieved, which isadvantageous. In addition, this embodiment mode describes an example inwhich a thin-film secondary battery is used as a storage capacitor inthe power supply circuit. Needless to say, instead of the secondarybattery, a capacitor such as an electric double layer capacitor may beused.

First, a peeling layer 1303 is formed over one surface of a substrate1301 with an insulating film 1302 interposed therebetween, and then aninsulating film 1304 functioning as a base film and a semiconductor film(e.g., a film containing amorphous silicon) 1305 are stacked thereover(see FIG. 6A). It is to be noted that the insulating film 1302, thepeeling layer 1303, the insulating film 1304, and the semiconductor film1305 can be formed consecutively.

The substrate 1301 is selected from a glass substrate, a quartzsubstrate, a metal substrate (e.g., a ceramic substrate or a stainlesssteel substrate), a semiconductor substrate such as a Si substrate, andthe like. Alternatively, a plastic substrate made of polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone(PES), acrylic, or the like can be used. In this process, although thepeeling layer 1303 is provided over the entire surface of the substrate1301 with the insulating film 1302 interposed therebetween, the peelinglayer 1303 can also be selectively formed by photolithography afterbeing provided over the entire surface of the substrate 1301.

The insulating films 1302 and 1304 are formed using insulating materialssuch as silicon oxide, silicon nitride, silicon oxynitride(SiO_(x)N_(y), where x>y>0), or silicon nitride oxide (SiN_(x)O_(y),where x>y>0) by a CVD method, a sputtering method, or the like. Forexample, when each of the insulating films 1302 and 1304 is formed tohave a two-layer structure, a silicon nitride oxide film may be formedas a first insulating film and a silicon oxynitride film may be formedas a second insulating film. In addition, a silicon nitride film may beformed as a first insulating film and a silicon oxide film may be formedas a second insulating film. The insulating film 1302 functions as ablocking layer which prevents an impurity element contained in thesubstrate 1301 from getting mixed into the peeling layer 1303 orelements formed thereover. The insulating film 1304 functions as ablocking layer which prevents an impurity element contained in thesubstrate 1301 or the peeling layer 1303 from getting mixed intoelements formed over the insulating film 1304. In this manner, providingthe insulating films 1302 and 1304 which function as the blocking layerscan prevent adverse effects on the elements formed over the peelinglayer 1303 or the insulating film 1304, which would otherwise be causedby an alkali metal such as Na or an alkaline earth metal contained inthe substrate 1301 or by the impurity element contained in the peelinglayer 1303. It is to be noted that when quartz is used for the substrate1301, for example, the insulating film 1302 may be omitted.

The peeling layer 1303 may be formed using a metal film, a stackedstructure of a metal film and a metal oxide film, or the like. As ametal film, either a single layer or stacked layers is/are formed usingan element selected from tungsten (W), molybdenum (Mo), titanium (Ti),tantalum (Ta), niobium (Nb), nickel (Ni), cobalt (Co), zirconium (Zr),zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os),and iridium (Ir), or an alloy material or a compound material containingsuch an element as its main component. In addition, such materials canbe formed by a sputtering method, various CVD methods such as a plasmaCVD method, or the like. A stacked structure of a metal film and a metaloxide film can be obtained by the steps of forming the above-describedmetal film, applying plasma treatment thereto under an oxygen atmosphereor an N₂O atmosphere or applying heat treatment thereto under an oxygenatmosphere or an N₂O atmosphere, and thereby forming oxide or oxynitrideof the metal film on the surface of the metal film. For example, when atungsten film is provided as a metal film by a sputtering method, a CVDmethod, or the like, a metal oxide film of tungsten oxide can be formedon the surface of the tungsten film by application of plasma treatmentto the tungsten film. When tungsten oxide is formed, there is noparticular limitation on the amount of oxygen, and thus, which of theabove oxides is to be formed may be determined based on the etching rateor the like. In addition, after a metal film (e.g., tungsten) is formed,an insulating film formed of silicon oxide (SiO₂) or the like may beformed over the metal film by a sputtering method, and also metal oxide(e.g., tungsten oxide on tungsten) may be formed on the metal film.Moreover, high-density-plasma treatment as described above may beapplied as the plasma treatment, for example. Besides, metal nitride ormetal oxynitride may also be formed. In that case, plasma treatment orheat treatment may be applied to the metal film under a nitrogenatmosphere or an atmosphere containing nitrogen and oxygen.

The amorphous semiconductor film 1305 is formed with a thickness of 25to 200 nm (preferably, 30 to 150 nm) by a sputtering method, an LPCVDmethod, a plasma CVD method, or the like.

Next, the amorphous semiconductor film 1305 is crystallized by laserirradiation.

Alternatively, the crystallization of the amorphous semiconductor film1305 may be performed by a method combining the laser crystallizationwith a thermal crystallization method using RTA or an annealing furnaceor with a thermal crystallization method using a metal element thatpromotes the crystallization. After that, the crystallized semiconductorfilm is etched into a desired shape, whereby crystalline semiconductorfilms 1305 a to 1305 f are formed. Then, a gate insulating film 1306 isformed so as to cover the semiconductor films 1305 a to 1305 f (see FIG.6B).

The gate insulating film 1306 is formed using an insulating materialsuch as silicon oxide, silicon nitride, silicon oxynitride(SiO_(x)N_(y), where x>y>0), or silicon nitride oxide (SiN_(x)O_(y),where x>y>0) by a CVD method, a sputtering method, or the like. Forexample, when the gate insulating film 1306 is formed to have atwo-layer structure, it is preferable to form a silicon oxynitride filmas a first insulating film and form a silicon nitride oxide film as asecond insulating film. Alternatively, it is also preferable to form asilicon oxide film as a first insulating film and form a silicon nitridefilm as a second insulating film.

An example of a formation process of the crystalline semiconductor films1305 a to 1305 f is briefly explained below. First, an amorphoussemiconductor film with a thickness of 50 to 60 nm is formed by a plasmaCVD method. Then, a solution containing nickel which is a metal elementthat promotes crystallization is retained on the amorphous semiconductorfilm, which is followed by dehydrogenation treatment (500° C. for onehour) and thermal crystallization treatment (550° C. for four hours).Thus, a crystalline semiconductor film is formed. Then, the crystallinesemiconductor film is subjected to laser irradiation and then aphotolithography process to form the crystalline semiconductor films1305 a to 1305 f. It is to be noted that crystallization of theamorphous semiconductor film may be performed only by laser irradiation,not by thermal crystallization which uses a metal element that promotescrystallization.

As a laser oscillator used for crystallization, either a continuous wavelaser oscillator (a CW laser oscillator) or a pulsed laser oscillatorcan be used. As a laser that can be used here, there are a gas lasersuch as an Ar laser, a Kr laser, or an excimer laser; a laser whosemedium is single-crystalline YAG, YVO₄, forsterite (Mg₂SiO₄), YAlO₃, orGdVO₄ or polycrystalline (ceramic) YAG, Y₂O₃, YVO₄, YAlO₃, or GdVO₄doped with one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as adopant; a glass laser; a ruby laser;

an alexandrite laser; a Ti:sapphire laser; a copper vapor laser; and agold vapor laser. When irradiation is performed with the fundamentalwave of such a laser beam or the second to fourth harmonics of such alaser beam, crystals with a large grain size can be obtained. Forexample, the second harmonic (532 nm) or the third harmonic (355 nm) ofan Nd:YVO₄ laser (the fundamental wave of 1064 nm) can be used. In thiscase, a laser power density of approximately 0.01 to 100 MW/cm²(preferably, 0.1 to 10 MW/cm²) is needed, and irradiation is performedwith a scanning rate of approximately 10 to 2000 cm/sec. It is to benoted that the laser whose medium is single crystalline YAG, YVO₄,forsterite (Mg₂SiO₄), YAlO₃, or GdVO₄ or polycrystalline (ceramic) YAG,Y₂O₃, YVO₄, YAlO₃, or GdVO₄ doped with one or more of Nd, Yb, Cr, Ti,Ho, Er, Tm, and Ta as a dopant; an Ar ion laser, or a Ti:sapphire lasercan be used as a CW laser, whereas it can also be used as a pulsed laserwith a repetition rate of 10 MHz or more by a Q-switch operation, modelocking, or the like. When a laser beam with a repetition rate of 10 MHzor more is used, a semiconductor film is irradiated with the next pulseduring the period in which the semiconductor film has been melted by thelaser beam and is solidified. Therefore, unlike the case of using apulsed laser with a low repetition rate, a solid-liquid interface in thesemiconductor film can be continuously moved. Thus, crystal grains whichhave grown continuously in the scanning direction can be obtained.

The gate insulating film 1306 may be formed by oxidization ornitridation of the surfaces of the semiconductor films 1305 a to 1305 fby the above-described high-density plasma treatment. For example,plasma treatment with a mixed gas of a rare gas such as He, Ar, Kr, orXe, and oxygen, nitrogen oxide (NO₂), ammonia, nitrogen, or hydrogen isconducted. When plasma is excited by the introduction of microwaves,plasma with a low electron temperature and high density can begenerated. With oxygen radicals (which may include OH radicals) ornitrogen radicals (which may include NH radicals) which are generated bythe high-density plasma, a surface of a semiconductor film can beoxidized or nitrided.

By such high-density plasma treatment, an insulating film with athickness of 1 to 20 nm, typically 5 to 10 nm, is formed on asemiconductor film. Since the reaction in this case is a solid-phasereaction, the interface state density between the insulating film andthe semiconductor film can be quite low. Since such high-density plasmatreatment directly. oxidizes (or nitrides) a semiconductor film(crystalline silicon or polycrystalline silicon), desirably, aninsulating film can be formed with extremely little unevenness. Inaddition, since crystal grain boundaries of crystalline silicon are notstrongly oxidized, an excellent state is obtained. That is, by thesolid-phase oxidation of a surface of a semiconductor film byhigh-density plasma treatment which is described in this embodimentmode, an insulating film with a uniform thickness and low interfacestate density can be formed without excessive oxidation reaction at thecrystal grain boundaries.

As the gate insulating film, only an insulating film formed byhigh-density plasma treatment may be used, or a stacked layer may beemployed, which is obtained by deposition of an insulating film such assilicon oxide, silicon oxynitride, or silicon nitride on the insulatingfilm, by a CVD method using plasma or thermal reaction. In either case,a transistor which includes such an insulating film formed byhigh-density plasma treatment in a part or the whole of its gateinsulating film can have reduced characteristic variations.

In addition, the semiconductor films 1305 a to 1305 f, which areobtained by irradiation of a semiconductor film with a continuous wavelaser beam or a laser beam oscillated with a repetition rate of 10 MHzor more and scanning the semiconductor film with the laser beam in onedirection to crystallize the semiconductor film, have a characteristicin that their crystals grow in the beam scanning direction. Transistorsare each arranged so that its channel length direction (direction inwhich carriers move when a channel formation region is formed) isaligned with the scanning direction, and the above-described gateinsulating film is combined with the semiconductor film, whereby thinfilm transistors (TFTs) with high electron field effect mobility andreduced variations in characteristics can be obtained.

Next, a first conductive film and a second conductive film are stackedover the gate insulating film 1306. Here, the first conductive film isformed to a thickness of 20 to 100 nm by a CVD method, a sputteringmethod, or the like. The second conductive film is formed to a thicknessof 100 to 400 nm. The first conductive film and the second conductivefilm are formed of an element selected from tantalum (Ta), tungsten (W),titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium(Cr), niobium (Nb), and the like, or an alloy material or a compoundmaterial containing such an element as its main component.Alternatively, a semiconductor material typified by polycrystallinesilicon doped with an impurity element such as phosphorus can also beused. As combination examples of the first conductive film and thesecond conductive film, a tantalum nitride film and a tungsten film; atungsten nitride film and a tungsten film; a molybdenum nitride film anda molybdenum film; and the like can be given. Tungsten and tantalumnitride have high heat resistance. Therefore, after forming the firstconductive film and the second conductive film, heat treatment for thepurpose of thermal activation can be applied thereto. In addition, inthe case where a two-layer structure is not employed, but a three-layerstructure is employed, it is preferable to use a stacked structure of amolybdenum film, an aluminum film, and a molybdenum film.

Next, a resist mask is formed by photolithography, and etching treatmentis conducted to form gate electrodes and gate lines. Thus, gateelectrodes 1307 are formed above the semiconductor films 1305 a to 1305f. Here, a stacked structure of a first conductive film 1307 a and asecond conductive film 1307 b is shown as an example of the gateelectrode 1307.

Next, the semiconductor films 1305 a to 1305 f are doped with an n-typeimpurity element at low concentration, using the gate electrodes 1307 asmasks by an ion doping method or an ion implantation method. Then, aresist mask is selectively formed by photolithography, and thesemiconductor films 1305 c and 1305 e are doped with a p-type impurityelement at high concentration. As an n-type impurity element, phosphorus(P), arsenic (As), or the like can be used. As a p-type impurityelement, boron (B), aluminum (Al), gallium (Ga), or the like can beused. Here, phosphorus (P) is used as an n-type impurity element and isselectively introduced into the semiconductor films 1305 a to 1305 f soas to be contained at concentrations of 1×10¹⁵ to 1×10¹⁹ /cm³. Thus,n-type impurity regions 1308 are formed. In addition, boron (B) is usedas a p-type impurity element, and is selectively introduced into thesemiconductor films 1305 c and 1305 e so as to be contained atconcentrations of 1×10¹⁹ to 1×10²⁰/cm³. Thus, p-type impurity regions1309 are formed (see FIG. 6C).

Subsequently, an insulating film is formed so as to cover the gateinsulating film 1306 and the gate electrodes 1307. The insulating filmis formed using either a single layer or a stacked layer of a filmcontaining an inorganic material such as silicon, silicon oxide, orsilicon nitride, or a film containing an organic material such as anorganic resin by a plasma CVD method, a sputtering method, or the like.Next, the insulating film is selectively etched by anisotropic etchingmainly in the perpendicular direction, so that insulating films 1310(also referred to as sidewalls) which are in contact with the sidesurfaces of the gate electrodes 1307 are formed. The insulating films1310 are used as masks in doping for forming LDD (Lightly Doped Drain)regions.

Next, the semiconductor films 1305 a, 1305 b, 1305 d, and 1305 f aredoped with an n-type impurity element at high concentration, usingresist masks formed by photolithography, the gate electrodes 1307, andthe insulating films 1310 as masks. Thus, n-type impurity regions 1311are formed. Here, phosphorus (P) is used as an n-type impurity element,and is selectively introduced into the semiconductor films 1305 a, 1305b, 1305 d, and 1305 f so as to be contained at concentrations of 1×10¹⁹to 1×10²⁰/cm³. Thus, the n-type impurity regions 1311 with higherconcentration of impurity than that of the impurity regions 1308 areformed.

Through the above steps, n-channel thin film transistors 1300 a, 1300 b,1300 d, and 1300 f, and p-channel thin film transistors 1300 c and 1300e are formed (see FIG. 6D).

In the n-channel thin film transistor 1300 a, a channel formation regionis formed in a region of the semiconductor film 1305 a which overlapswith the gate electrode 1307; the impurity regions 1311 serving assource and drain regions are formed in regions of the semiconductor film1305 a which do not overlap with the gate electrode 1307 and theinsulating film 1310; and low concentration impurity regions (LDDregions) are formed in regions of the semiconductor film 1305 a whichoverlap with the insulating film 1310, between the channel formationregion and the impurity regions 1311. Similarly, channel formationregions, low concentration impurity regions, and the impurity regions1311 are formed in the n-channel thin film transistors 1300 b, 1300 d,and 1300 f.

In the p-channel thin film transistor 1300 c, a channel formation regionis formed in a region of the semiconductor film 1305 c which overlapswith the gate electrode 1307, and the impurity regions 1309 serving assource and drain regions are formed in regions of the semiconductor film1305 c which do not overlap with the gate electrode 1307. Similarly, achannel formation region and the impurity regions 1309 are formed in thep-channel thin film transistor 1300 e. Here, although LDD regions arenot formed in the p-channel thin film transistors 1300 c and 1300 e, LDDregions may be provided in the p-channel thin film transistors or astructure without LDD regions may be applied to the n-channel thin filmtransistors.

Next, an insulating film with a single layer structure or a stackedlayer structure is formed so as to cover the semiconductor films 1305 ato 1305 f, the gate electrodes 1307, and the like. Then, conductivefilms 1313 electrically connected to the impurity regions 1309 and 1311which serve as the source and drain regions of the thin film transistors1300 a to 1300 f are formed over the insulating film (see FIG. 7A). Theinsulating film is formed with a single layer or a stacked layer, usingan inorganic material such as silicon oxide or silicon nitride, anorganic material such as polyimide, polyamide, benzocyclobutene,acrylic, or epoxy, a siloxane material, or the like by a CVD method, asputtering method, an SOG method, a droplet discharging method, a screenprinting method, or the like. In this embodiment mode, the insulatingfilm is formed to have a two-layer structure, and a silicon nitrideoxide film is formed as a first insulating film 1312 a and a siliconoxynitride film is formed as a second insulating film 1312 b. Inaddition, the conductive films 1313 can form the source and drainelectrodes of the thin film transistors 1300 a to 1300 f.

Before the insulating films 1312 a and 1312 b are formed or after one orboth of the insulating films 1312 a and 1312 b is/are formed, heattreatment is preferably conducted for recovery of the crystallinity ofthe semiconductor films, activation of the impurity element which hasbeen added into the semiconductor films, or hydrogenation of thesemiconductor films. As the heat treatment, thermal annealing, laserannealing, RTA, or the like may be applied.

The conductive films 1313 are formed with a single layer or a stackedlayer of an element selected from aluminum (Al), tungsten (W), titanium(Ti), tantalum (Ta), molybdenum (Mo), nickel (Ni), platinum (Pt), copper(Cu), gold (Au), silver (Ag), manganese (Mn), neodymium (Nd), carbon(C), and silicon (Si), or an alloy material or a compound materialcontaining the element as its main component by a CVD method, asputtering method, or the like. An alloy material containing aluminum asits main component corresponds to, for example, a material whichcontains aluminum as its main component and also contains nickel, or amaterial which contains aluminum as its main component and also containsnickel and one or both of carbon and silicon. The conductive films 1313are preferably formed to have a stacked structure of a barrier film, analuminum silicon (Al—Si) film, and a barrier film or a stacked structureof a barrier film, an aluminum silicon (Al—Si) film, a titanium nitridefilm, and a barrier film. Note that the “barrier film” corresponds to athin film formed of titanium, titanium nitride, molybdenum, ormolybdenum nitride. Aluminum and aluminum silicon are suitable materialsfor forming the conductive films 1313 because they have low resistancevalue and are inexpensive. When barrier layers are provided as the toplayer and the bottom layer, generation of hillocks of aluminum oraluminum silicon can be prevented. In addition, when a barrier film isformed of titanium which is an element having a high reducing property,even if a thin natural oxide film is formed on the crystallinesemiconductor film, the natural oxide film can be reduced, and afavorable contact between the conductive film 1313 and the crystallinesemiconductor film can be obtained.

Next, an insulating film 1314 is formed so as to cover the conductivefilms 1313, and conductive films 1315 a and 1315 b electricallyconnected to the conductive films 1313 which form the source electrodesor the drain electrodes of the thin film transistors 1300 a and 1300 fare formed over the insulating film 1314. In addition, a conductive film1316 electrically connected to the conductive film 1313 which forms thesource electrode or drain electrode of the thin film transistor 1300 bis formed. It is to be noted that the conductive films 1315 a and 1315 band the conductive film 1316 may be formed using the same material atthe same time. The conductive films 1315 a and 1315 b and the conductivefilm 1316 can be formed using any of the above-described materials forthe conductive film 1313.

Next, a conductive film 1317 functioning as an antenna is formed so asto be electrically connected to the conductive film 1316 (see FIG. 7B).

The insulating film 1314 can be formed with a single layer or a stackedlayer of an insulating film containing oxygen and/or nitrogen such assilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y) where x>y>0), or silicon nitride oxide (SiN_(x)O_(y) wherex>y>0); a film containing carbon such as DLC (Diamond-Like Carbon); anorganic material such as epoxy, polyimide, polyamide, polyvinyl phenol,benzocyclobutene, or acrylic; or a siloxane material such as a siloxaneresin by a CVD method, a sputtering method, or the like. It is to benoted that a siloxane material corresponds to a material having a bondof Si—O—Si. Siloxane has a skeleton structure with the bond of silicon(Si) and oxygen (O). As a substituent of siloxane, an organic groupcontaining at least hydrogen (e.g., an alkyl group or aromatichydrocarbon) is used. In addition, a fluoro group may be used as thesubstituent. Further, both a fluoro group and an organic groupcontaining at least hydrogen may be used as the substituent.

The conductive film 1317 is formed of a conductive material by a CVDmethod, a sputtering method, a printing method such as screen printingor gravure printing, a droplet discharging method, a dispenser method, aplating method, or the like. The conductive film 1317 is formed with asingle layer or a stacked layer of an element selected from aluminum(Al), titanium (Ti), silver (Ag), copper (Cu), gold (Au), platinum (Pt),nickel (Ni), palladium (Pd), tantalum (Ta), and molybdenum (Mo), or analloy material or a compound material containing such an element as itsmain component.

For example, when the conductive film 1317 functioning as an antenna isformed by a screen printing method, the conductive film 1317 can beprovided by selective printing of a conductive paste in which conductiveparticles with a grain diameter of several nanometers to several tens ofmicrometers are dissolved or dispersed in an organic resin. Theconductive particles can be at least one or more of metal particlesselected from silver (Ag), gold (Au), copper (Cu), nickel (Ni), platinum(Pt), palladium (Pd), tantalum (Ta), molybdenum (Mo), titanium (Ti), andthe like; fine particles of silver halide; and dispersive nanoparticlesthereof. In addition, the organic resin included in the conductive pastecan be one or more of organic resins which function as a binder, asolvent, a dispersing agent, and a coating material of the metalparticles. Typically, organic resins such as an epoxy resin and asilicone resin can be given as examples. Preferably, a conductive pasteis extruded and then baked to form the conductive film. For example, inthe case of using fine particles (e.g., a grain diameter of 1 to 100 nm)containing silver as its main component as a material of the conductivepaste, the conductive paste is baked and hardened at temperatures of 150to 300° C., so that the conductive film can be obtained. Alternatively,it is also possible to use fine particles containing solder or lead-freesolder as its main component. In that case, fine particles with a graindiameter of 20 μm or less are preferably used. Solder and lead-freesolder have the advantage of low cost.

The conductive films 1315 a and 1315 b can function as wirings which areelectrically connected to a secondary battery included in thesemiconductor device of the present invention in a later step. Inaddition, in forming the conductive film 1317 which functions as anantenna, other conductive films may be separately formed so as to beelectrically connected to the conductive films 1315 a and 1315 b, sothat the conductive films can be utilized as the wirings for connectingthe conductive films 1315 a and 1315 b to the secondary battery.

Next, after forming an insulating film 1318 so as to cover theconductive film 1317, a layer including the thin film transistors 1300 ato 1300 f, the conductive film 1317, and the like (hereinafter referredto as an “element formation layer 1319”) is peeled off the substrate1301. Here, after forming opening portions in the element formationlayer 1319 excluding the region of the thin film transistors 1300 a to1300 f by laser irradiation (e.g., with UV light) (see FIG. 7C), theelement formation layer 1319 can be peeled off the substrate 1301 with aphysical force. The peeling layer 1303 may be selectively removed byintroduction of an etchant into the opening portions before peeling theelement formation layer 1319 off the substrate 1301. As the etchant, agas or a liquid containing halogen fluoride or an interhalogen compoundis used. For example, when chlorine trifluoride (ClF₃) is used as thegas containing halogen fluoride, the element formation layer 1319 ispeeled off the substrate 1301. The whole peeling layer 1303 does notnecessarily be removed but part thereof may be left. Accordingly, theconsumption of the etchant can be suppressed and process time needed forremoving the peeling layer can be shortened. In addition, even afterremoving the peeling layer 1303, the element formation layer 1319 can beheld above the substrate 1301. In addition, by reuse of the substrate1301 from which the element formation layer 1319 has been peeled, costreduction can be achieved.

The insulating film 1318 can be formed with a single layer or a stackedlayer of an insulating film containing oxygen and/or nitrogen such assilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y) where x>y>0), or silicon nitride oxide (SiN_(x)O_(y) wherex>y>0); a film containing carbon such as DLC (Diamond-Like Carbon); anorganic material such as epoxy, polyimide, polyamide, polyvinyl phenol,benzocyclobutene, or acrylic; or a siloxane material such as a siloxaneresin by a CVD method, a sputtering method, or the like.

In this embodiment mode, after forming the opening portions in theelement formation layer 1319 by laser irradiation, a first sheetmaterial 1320 is attached to one surface of the element formation layer1319 (the surface where the insulating film 1318 is exposed), and thenthe element formation layer 1319 is peeled off the substrate 1301 (seeFIG. 8A).

Next, a second sheet material 1321 is provided for the other surface ofthe element formation layer 1319 (the surface exposed by peeling),followed by one or both of heat treatment and pressurization treatmentfor attachment of the second sheet material 1321 (see FIG. 8B). Thefirst sheet material 1320 and the second sheet material 1321 functionsas substrates, and a plastic film such as a hot-melt film can be used.In addition, without being limited to such plastic films, a substratehaving an insulating surface, such as a glass substrate, can be used.

As the first sheet material 1320 and the second sheet material 1321, afilm on which antistatic treatment for preventing static electricity orthe like has been applied (hereinafter referred to as an antistaticfilm) can also be used. As examples of the antistatic film, a film inwhich an antistatic material is dispersed in a resin, a film to which anantistatic material is attached, and the like can be given. The filmprovided with an antistatic material can be a film with an antistaticmaterial provided on one of its surfaces, or a film with an antistaticmaterial provided on each of its surfaces. The film with an antistaticmaterial provided on one of its surfaces may be attached to the layer sothat the antistatic material is placed on the inner side of the film orthe outer side of the film. The antistatic material may be provided overthe entire surface of the film, or over a part of the film. As anantistatic material, a metal, indium tin oxide (ITO), or a surfactantsuch as an amphoteric surfactant, a cationic surfactant, or a nonionicsurfactant can be used. Further, as an antistatic material, a resinmaterial which contains a cross-linked copolymer having a carboxyl groupand a quaternary ammonium base on its side chain, or the like can beused. Such a material is attached, mixed, or applied to a film, so thatan antistatic film can be formed. The element formation layer is sealedusing the antistatic film, so that the semiconductor elements can beprotected from adverse effects such as external static electricity whendealt with as a commercial product.

It is to be noted that a thin-film secondary battery is connected to theconductive films 1315 a and 1315 b, so that the storage capacitor of thepower supply circuit is formed. The connection with the secondarybattery may be conducted before the element formation layer 1319 ispeeled off the substrate 1301 (at the stage shown in FIG. 7B or FIG.7C), after the element formation layer 1319 is peeled off the substrate1301 (at the stage shown in FIG. 8A), or after the element formationlayer 1319 is sealed with the first sheet material 1320 and the secondsheet material 1321 (at the stage shown in FIG. 8B). An example wherethe element formation layer 1319 and the secondary battery are formed tobe connected is explained below with reference to FIGS. 9A and 9B andFIGS. 10A and 10B.

At the stage shown in FIG. 7B, conductive films 1331 a and 1331 b whichare electrically connected to the conductive films 1315 a and 1315 b,respectively are formed at the same time as the conductive film 1317which functions as an antenna. Then, the insulating film 1318 is formedso as to cover the conductive films 1317, 1331 a, and 1331 b, followedby formation of opening portions so that the surfaces of the conductivefilms 1331 a and 1331 b are exposed. After that, the opening portionsare formed in the element formation layer 1319 by laser irradiation, andthen the first sheet material 1320 is attached to one surface of theelement formation layer 1319 (the surface where the insulating film 1318is exposed), so that the element formation layer 1319 is peeled off thesubstrate 1301 (see FIG. 9A).

Next, the second sheet material 1321 is attached to the other surface ofthe element formation layer 1319 (the surface exposed by peeling), andthe element formation layer 1319 is peeled off the first sheet material1320. Therefore, a material with low viscosity is used as the firstsheet material 1320. Then, conductive films 1334 a and 1334 b which areelectrically connected to the conductive films 1331 a and 1331 brespectively through the opening portions are selectively formed (seeFIG. 9B).

The conductive films 1334 a and 1334 b are formed of a conductivematerial by a CVD method, a sputtering method, a printing method such asscreen printing or gravure printing, a droplet discharging method, adispenser method, a plating method, or the like. The conductive films1334 a and 1334 b are formed with a single layer or a stacked layer ofan element selected from aluminum (Al), titanium (Ti), silver (Ag),copper (Cu), gold (Au), platinum (Pt), nickel (Ni), palladium (Pd),tantalum (Ta), and molybdenum (Mo), or an alloy material or a compoundmaterial containing the element as its main component.

Although the example shown in this embodiment mode is the case where theconductive films 1334 a. and 1334 b are formed after peeling the elementformation layer 1319 off the substrate 1301, the element formation layer1319 may be peeled off the substrate 1301 after the formation of theconductive films 1334 a and 1334 b.

Next, in the case where a plurality of elements are formed over thesubstrate, the element formation layer 1319 is cut into elements (seeFIG. 10A). A laser irradiation apparatus, a dicing apparatus, a scribingapparatus, or the like can be used for the cutting.

At this time, the plurality of elements formed over one substrate areseparated from one another by laser irradiation.

Next, the separated elements are electrically connected to the secondarybattery (see FIG. 10B). In this embodiment mode, a thin-film secondarybattery is used as the storage capacitor of the power supply circuit, inwhich a current-collecting thin film, a negative electrode activematerial layer, a solid electrolyte layer, a positive electrode activematerial layer, and a current-collecting thin film are sequentiallystacked.

Conductive films 1336 a and 1336 b are formed of a conductive materialby a CVD method, a sputtering method, a printing method such as screenprinting or gravure printing, a droplet discharging method, a dispensermethod, a plating method, or the like. The conductive films 1336 a and1336 b are formed with a single layer or a stacked layer of an elementselected from aluminum (Al), titanium (Ti), silver (Ag), copper (Cu),gold (Au), platinum (Pt), nickel (Ni), palladium (Pd), tantalum (Ta),and molybdenum (Mo), or an alloy material or a compound materialcontaining such an element as its main component. The conductivematerial should have high adhesion to a negative electrode activematerial layer and also low resistance. In particular, aluminum, copper,nickel, vanadium, or the like is preferably used.

The structure of a thin-film secondary battery 1389 is described next. Anegative electrode active material layer 1381 is formed over theconductive film 1336 a. In general, vanadium oxide (V₂O₅) or the like isused. Next, a solid electrolyte layer 1382 is formed over the negativeelectrode active material layer 1381. In general, lithium phosphate(Li₃PO₄) or the like is used. Next, a positive electrode active materiallayer 1383 is formed over the solid electrolyte layer 1382. In general,lithium manganate (LiMn₂O₄) or the like is used. Lithium cobaltate(LiCoO₂) or lithium nickel oxide (LiNiO₂) may also be used. Next, acurrent-collecting thin film 1384 to serve as an electrode is formedover the positive electrode active material layer 1383. Thecurrent-collecting thin film 1384 should have high adhesion to thepositive electrode active material layer 1383 and also low resistance.For example, aluminum, copper, nickel, vanadium, or the like can beused.

Each of the above thin layers of the negative electrode active materiallayer 1381, the solid electrolyte layer 1382, the positive electrodeactive material layer 1383, and the current-collecting thin film 1384may be formed by a sputtering technique or an evaporation technique. Inaddition, the thickness of each layer is preferably 0.1 to 3 μm.

Next, an interlayer film 1385 is formed by application of a resin. Theinterlayer film 1385 is etched to form a contact hole. The interlayerfilm 1385 is not limited to a resin, and other films such as an oxidefilm formed by CVD method or the like may be used as well; however, aresin is preferably used in terms of flatness. Alternatively, thecontact hole may be formed without using etching, but using aphotosensitive resin. Next, a wiring layer 1386 is formed over theinterlayer film 1385 and connected to the conductive film 1336 b. Thus,an electrical connection of the thin-film secondary battery is secured.

Here, the conductive films 1334 a and 1334 b which are provided in theelement formation layer 1319 are connected to the conductive films 1336a and 1336 b respectively in advance, which serve as the connectionterminals of the thin-film secondary battery 1389. Here, an example isshown in which an electrical connection between the conductive films1334 a and 1336 a or an electrical connection between the conductivefilms 1334 b and 1336 b is performed by pressure bonding with anadhesive material such as an anisotropic conductive film (ACF) or ananisotropic conductive paste (ACP) interposed therebetween. In thisembodiment mode, the example is shown, in which the connection isperformed using conductive particles 1338 included in an adhesive resin1337. Alternatively, a conductive adhesive such as a silver paste, acopper paste, or a carbon paste; solder joint; or the like can be used.

The structures of such transistors can be various without being limitedto the specific structures shown in this embodiment mode. For example, amulti-gate structure having two or more gate electrodes may be employed.When a multi-gate structure is employed, a structure in which channelregions are connected in series is provided; therefore, a structure inwhich a plurality of transistors are connected in series is provided.When a multi-gate structure is employed, various advantages can beobtained in that off-current can be reduced; withstand voltage of thetransistor can be increased, so that the reliability is increased; andeven if drain-source voltage changes when the transistor operates in thesaturation region, a drain-source current does not change very much, andthus flat characteristics can be obtained. In addition, a structure inwhich gate electrodes are formed above and below a channel may also beemployed. When a structure in which gate electrodes are formed above andbelow a channel is employed, the channel region is enlarged and theamount of current flowing therethrough can be increased. Thus, adepletion layer can be easily formed and the subthreshold swing (Svalue) can be decreased. When gate electrodes are formed above and belowa channel, a structure in which a plurality of transistors are connectedin parallel is provided.

In addition, the transistors may have any of the following structures: astructure in which a gate electrode is formed above a channel; astructure in which a gate electrode is formed below a channel; astaggered structure; an inverted staggered structure. In addition, thetransistors may have a structure in which a channel region is dividedinto a plurality of regions and the divided regions are connected inparallel or in series. In addition, a channel (or part thereof) mayoverlap with a source electrode or a drain electrode. When a structurein which a channel (or part thereof) overlaps with a source electrode ora drain electrode is employed, electric charges can be prevented frombeing accumulated in part of the channel and thus an unstable operationcan be prevented. In addition, an LDD (Lightly Doped Drain) region maybe provided. When an LDD region is provided, off-current can be reduced;the withstand voltage of the transistor can be increased, so that thereliability is increased; and even if drain-source voltage changes whenthe transistor operates in the saturation region, drain-source currentdoes not change very much, and thus flat characteristics can beobtained.

The method for manufacturing the semiconductor device in this embodimentmode can be applied to any of the semiconductor devices in the otherembodiment modes.

(Embodiment Mode 5)

Embodiment Mode 5 describes an example of a method for manufacturing thesemiconductor device described in the above embodiment modes, withreference to drawings. This embodiment mode describes a structure inwhich an antenna circuit and a power supply circuit in a CPU are formedover the same substrate. It is to be noted that an antenna circuit and apower supply circuit are formed using transistors including channelformation regions formed on a single crystal substrate, at a time overthe same substrate. When transistors formed using a single crystalsubstrate are used as the transistors, a semiconductor device havingtransistors with few characteristic variations can be formed, which ispreferable. In addition, this embodiment mode describes an example inwhich the thin-film secondary battery described in Embodiment Mode 4 isused as the storage capacitor of the power supply circuit.

First, insulating films (also referred to as field oxide films) 2302 areformed on a semiconductor substrate 2300 to form regions (also referredto as element formation regions or element separation regions) 2304 and2306 (see FIG. 11A). The regions 2304 and 2306 provided in thesemiconductor substrate 2300 are insulated from each other by theinsulating film 2302. The example shown here is the case where a singlecrystal Si substrate having n-type conductivity is used as thesemiconductor substrate 2300, and a p well 2307 is formed in the region2306 of the semiconductor substrate 2300.

Any substrate can be used as the substrate 2300 as long as it is asemiconductor substrate. For example, a single crystal Si substratehaving n-type or p-type conductivity, a compound semiconductor substrate(e.g., a GaAs substrate, an InP substrate, a GaN substrate, a SiCsubstrate, a sapphire substrate, or a ZnSe substrate), an SOI (Siliconon Insulator) substrate formed by a bonding method or a SIMOX(Separation by. IMplanted OXygen) method, or the like can be used.

The regions 2304 and 2306 can be formed by a LOCOS (LOCal Oxidation ofSilicon) method, a trench isolation method, or the like.

In addition, the p well 2307 formed in the region 2306 of thesemiconductor substrate 2300 can be formed by selective doping of thesemiconductor substrate 2300 with a p-type impurity element. As a p-typeimpurity element, boron (B), aluminum (Al), gallium (Ga), or the likecan be used.

In this embodiment mode, although the region 2304 is not doped with animpurity element because a semiconductor substrate having n-typeconductivity is used as the semiconductor substrate 2300, an n well maybe formed in the region 2304 by introduction of an n-type impurityelement. As an n-type impurity element, phosphorus (P), arsenic (As), orthe like can be used. When a semiconductor substrate having p-typeconductivity is used, on the other hand, the region 2304 may be dopedwith an n-type impurity element to form an n well, whereas the region2306 may be doped with no impurity element.

Next, insulating films 2332 and 2334 are formed so as to cover theregions 2304 and 2306, respectively (see FIG. 11B).

For example, surfaces of the regions 2304 and 2306 provided in thesemiconductor substrate 2300 are oxidized by heat treatment, so that theinsulating films 2332 and 2334 can be formed of silicon oxide films.Alternatively, the insulating films 2332 and 2334 may be formed to havea stacked structure of a silicon oxide film and a film containing oxygenand nitrogen (a silicon oxynitride film) by the steps of forming asilicon oxide film by a thermal oxidation method and then nitriding thesurface of the silicon oxide film by nitridation treatment.

Further alternatively, the insulating films 2332 and 2334 can be formedby plasma treatment as described above. For example, the insulatingfilms 2332 and 2334 can be formed using a silicon oxide (SiO_(x)) filmor a silicon nitride (SiN_(x)) film which is obtained by application ofhigh-density plasma oxidation or high-density plasma nitridationtreatment to the surfaces of the regions 2304 and 2306 provided in thesemiconductor substrate 2300. Furthermore, after applying high-densityplasma oxidation treatment to the surfaces of the regions 2304 and 2306,high-density plasma nitridation treatment may be performed. In thatcase, silicon oxide films are formed on the surfaces of the regions 2304and 2306, and then silicon oxynitride films are formed on the siliconoxide films. Thus, the insulating films 2332 and 2334 are each formed tohave a stacked structure of the silicon oxide film and the siliconoxynitride film. In addition, after silicon oxide films are formed onthe surfaces of the regions 2304 and 2306 by a thermal oxidation method,high-density plasma oxidation or high-density nitridation treatment maybe applied to the silicon oxide films.

The insulating films 2332 and 2334 formed over the regions 2304 and 2306of the semiconductor substrate 2300 respectively function as the gateinsulating films of transistors which are completed later.

Next, a conductive film is formed so as to cover the insulating films2332 and 2334 which are formed over the regions 2304 and 2306,respectively (see FIG. 11C). Here, an example is shown in which theconductive film is formed by sequentially stacking conductive films 2336and 2338. Needless to say, the conductive film may be formed using asingle layer or a stacked structure of three or more layers.

As materials of the conductive films 2336 and 2338, an element selectedfrom tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo),aluminum (Al), copper (Cu), chromium (Cr), niobium (Nb), and the like,or an alloy material or a compound material containing such an elementas its main component can be used. Alternatively, a metal nitride filmobtained by nitridation of the above element can be used. Besides, asemiconductor material typified by polycrystalline silicon doped with animpurity element such as phosphorus can be used.

In this case, a stacked structure is employed in which the conductivefilm 2336 is formed using tantalum nitride and the conductive film 2338is formed thereover using tungsten. Alternatively, it is also possibleto form the conductive film 2336 using a single-layer film or a stackedfilm of tungsten nitride, molybdenum nitride, and/or titanium nitrideand form the conductive film 2338 using a single-layer film or a stackedfilm of tantalum, molybdenum, and/or titanium.

Next, the stacked conductive films 2336 and 2338 are selectively removedby etching, so that the conductive films 2336 and 2338 remain above partof the regions 2304 and 2306, respectively. Thus, gate electrodes 2340and 2342 are formed (see FIG. 12A).

Next, a resist mask 2348 is selectively formed so as to cover the region2304, and the region 2306 is doped with an impurity element, using theresist mask 2348 and the gate electrode 2342 as masks, so that impurityregions are formed (see FIG. 12B). As an impurity element, an n-typeimpurity element or a p-type impurity element is used. As an n-typeimpurity element, phosphorus (P), arsenic (As), or the like can be used.As a p-type impurity element, boron (B), aluminum (Al), gallium (Ga), orthe like can be used. Here, phosphorus (P) is used as the impurityelement.

In FIG. 12B, by introduction of an impurity element, impurity regions2352 which form source and drain regions and a channel formation region2350 are formed in the region 2306.

Next, a resist mask 2366 is selectively formed so as to cover the region2306, and the region 2304 is doped with an impurity element, using theresist mask 2366 and the gate electrode 2340 as masks, so that impurityregions are formed (see FIG. 12C). As the impurity element, an n-typeimpurity element or a p-type impurity element is used. As an n-typeimpurity element, phosphorus (P), arsenic (As), or the like can be used.As a p-type impurity element, boron (B), aluminum (Al), gallium (Ga), orthe like can be used. At this time, an impurity element (e.g., boron(B)) of a conductivity type different from that of the impurity elementintroduced into the region 2306 in FIG. 12B is used. As a result,impurity regions 2370 which form source and drain regions and a channelformation region 2368 are formed in the region 2304.

Next, a second insulating film 2372 is formed so as to cover theinsulating films 2332 and 2334 and the gate electrodes 2340 and 2342.Then, wirings 2374, which are electrically connected to the impurityregions 2352 and 2370 formed in the regions 2306 and 2304 respectively,are formed over the second insulating film 2372 (see FIG. 13A).

The second insulating film 2372 can be formed with a single layer or astacked layer of an insulating film containing oxygen and/or nitrogensuch as silicon oxide (SiO_(x)), silicon nitride (SiN_(x)), siliconoxynitride (SiO_(x)N_(y) where x>y>0), or silicon nitride oxide(SiN_(x)O_(y) where x>y>0); a film containing carbon such as DLC(Diamond-Like Carbon); an organic material such as epoxy, polyimide,polyamide, polyvinyl phenol, benzocyclobutene, or acrylic; or a siloxanematerial such as a siloxane resin by a CVD method, a sputtering methodor the like. A siloxane material corresponds to a material having a bondof Si—O—Si. Siloxane has a skeleton structure with the bond of silicon(Si) and oxygen (O). As a substituent of siloxane, an organic groupcontaining at least hydrogen (e.g., an alkyl group or aromatichydrocarbon) is used. Also, a fluoro group may be used as thesubstituent, or both a fluoro group and an organic group containing atleast hydrogen may be used.

The wirings 2374 are formed with a single layer or a stacked layer of anelement selected from aluminum (Al), tungsten (W), titanium (Ti),tantalum (Ta), molybdenum (Mo), nickel (Ni), platinum (Pt), copper (Cu),gold (Au), silver (Ag), manganese (Mn), neodymium (Nd), carbon (C), andsilicon (Si), or an alloy material or a compound material containingsuch an element as its main component by a CVD method, a sputteringmethod, or the like. An alloy material containing aluminum as its maincomponent corresponds to, for example, a material which containsaluminum as its main component and also contains nickel, or a materialwhich contains aluminum as its main component and also contains nickeland one or both of carbon and silicon. The wirings 2374 are preferablyformed to have a stacked structure of a barrier film, analuminum-silicon (Al—Si) film, and a barrier film or a stacked structureof a barrier film, an aluminum-silicon (Al—Si) film, a titanium nitridefilm, and a barrier film. It is to be noted that the “barrier film”corresponds to a thin film formed of titanium, titanium nitride,molybdenum, or molybdenum nitride. Aluminum and aluminum silicon aresuitable materials for forming the wirings 2374 because they have lowresistance values and are inexpensive. When barrier layers are providedas the top layer and the bottom layer, generation of hillocks ofaluminum or aluminum silicon can be prevented. When a barrier film isformed of titanium which is an element having a high reducing property,even if a thin natural oxide film is formed on the crystallinesemiconductor film, the natural oxide film can be reduced, and afavorable contact between the wirings 2374 and the crystallinesemiconductor film can be obtained.

It is to be noted that the structure of transistors of the presentinvention is not limited to the one shown in the drawing. For example, atransistor with an inverted staggered structure, a FinFET structure, orthe like can be used. A FinFET structure is preferable because it cansuppress a short channel effect which occurs along with reduction intransistor size.

The semiconductor device of the present invention includes the storagecapacitor by which power can be stored in the power supply circuit ofthe CPU. As the storage capacitor, a capacitor such as an electricdouble layer capacitor or a thin-film secondary battery is preferablyused. In this embodiment mode, a connection between the transistorformed in this embodiment mode and a thin-film secondary battery isexplained.

In this embodiment mode, the secondary battery is stacked over thewiring 2374 connected to the transistor. The secondary battery has astructure in which a current-collecting thin film, a negative electrodeactive material layer, a solid electrolyte layer, a positive electrodeactive material layer, and a current-collecting thin film aresequentially stacked (see FIG. 13B). Therefore, the material of thewiring 2374 which also has a function of the current-collecting thinfilm of the secondary battery should have high adhesion to the negativeelectrode active material layer and also low resistance. In particular,aluminum, copper, nickel, vanadium, or the like is preferably used.

Subsequently, the structure of the thin-film secondary battery isdescribed. A negative electrode active material layer 2391 is formedover the wiring 2374. In general, vanadium oxide (V₂O₅) or the like isused. Next, a solid electrolyte layer 2392 is formed over the negativeelectrode active material layer 2391. In general, lithium phosphate(Li₃PO₄) or the like is used. Next, a positive electrode active materiallayer 2393 is formed over the solid electrolyte layer 2392. In general,lithium manganate (LiMn₂O₄) or the like is used. Lithium cobaltate(LiCoO₂) or lithium nickel oxide (LiNiO₂) may also be used. Next, acurrent-collecting thin film 2394 to serve as an electrode is formedover the positive electrode active material layer 2393. Thecurrent-collecting thin film 2394 should have high adhesion to thepositive electrode active material layer 2393 and also low resistance.For example, aluminum, copper, nickel, vanadium, or the like can beused.

Each of the above-described thin layers of the negative electrode activematerial layer 2391, the solid electrolyte layer 2392, the positiveelectrode active material layer 2393, and the current-collecting thinfilm 2394 may be formed by a sputtering technique or an evaporationtechnique. In addition, the thickness of each layer is preferably 0.1 to3 μm.

Next, an interlayer film 2396 is formed by application of a resin. Theinterlayer film 2396 is etched to form a contact hole. The interlayerfilm is not limited to a resin, and other films such as an oxide filmformed by CVD method or the like may also be used; however, a resin ispreferably used in terms of flatness. In addition, the contact hole maybe formed without etching, but using a photosensitive resin. Next, awiring layer 2395 is formed over the interlayer film 2396 and connectedto a wiring 2397. Thus, an electrical connection of the secondarybattery is secured.

With the above-described structure, the semiconductor device of thepresent invention can have a structure in which transistors are formedon a single crystal substrate and a thin-film secondary battery isformed thereover. Thus, by achieving thinning and reduction in size ofthe CPU, the semiconductor device of the present invention having a lotof flexibility in physical form can be provided.

The method for manufacturing the semiconductor device in this embodimentmode can be applied to any of the semiconductor devices in the otherembodiment modes.

(Embodiment Mode 6)

Embodiment Mode 6 describes an example of a method for manufacturing asemiconductor device, which is different from that described inEmbodiment Mode 4, with reference to drawings.

First, an insulating film is formed over a substrate 2600. Here, asingle crystal Si substrate having n-type conductivity is used as thesubstrate 2600, and insulating films 2602 and 2604 are formed over thesubstrate 2600 (see FIG. 14A). For example, silicon oxide (SiO_(x)) isformed as the insulating film 2602 by application of heat treatment tothe substrate 2600, and then silicon nitride (SiN_(x)) is formed overthe insulating film 2602 by a CVD method.

Any substrate can be used as the substrate 2600 as long as it is asemiconductor substrate, without particular limitations. For example, asingle crystal Si substrate having n-type or p-type conductivity, acompound semiconductor substrate (e.g., a GaAs substrate, an InPsubstrate, a GaN substrate, a SiC substrate, a sapphire substrate, or aZnSe substrate), an SOI (Silicon on Insulator) substrate formed by abonding method or a SIMOX (Separation by IMplanted OXygen) method, orthe like can be used.

In addition, the insulating film 2604 may be formed by nitridation ofthe insulating film 2602 by high-density plasma treatment, after formingthe insulating film 2602. It is to be noted that the insulating filmprovided over the substrate 2600 may have a single-layer structure or astacked structure of three or more layers.

Next, patterns of a resist mask 2606 are selectively formed over theinsulating film 2604, and selective etching is performed using theresist mask 2606 as a mask, so that recessed portions 2608 areselectively formed in the substrate 2600 (see FIG. 14B). For the etchingof the substrate 2600 and the insulating films 2602 and 2604, plasma dryetching can be conducted.

Next, the patterns of the resist mask 2606 are removed, and then aninsulating film 2610 is formed so as to fill the recessed portions 2608formed in the substrate 2600 (see FIG. 14C).

The insulating film 2610 is formed of an insulating material such assilicon oxide, silicon nitride, silicon oxynitride (SiO_(x)N_(y), wherex>y>0), or silicon nitride oxide (SiN_(x)O_(y), where x>y>0) by a CVDmethod, a sputtering method, or the like. As the insulating film 2610, asilicon oxide film is formed by an atmospheric pressure CVD method or alow-pressure CVD method using a TEOS (tetraethyl orthosilicate) gas.

Next, the surface of the substrate 2600 is exposed by grinding treatmentor polishing treatment such as CMP (Chemical Mechanical Polishing).Here, by exposure of the surface of the substrate 2600, regions 2612 and2613 are formed between insulating films 2611 which are formed in therecessed portions 2608 of the substrate 2600. The insulating film 2610formed over the surface of the substrate 2600 is removed by grindingtreatment or polishing treatment such as CMP, so that the insulatingfilms 2611 are obtained. Subsequently, by selective introduction of ap-type impurity element, a p well 2615 is formed in the region 2613 ofthe substrate 2600 (see FIG. 15A).

As a p-type impurity element, boron (B), aluminum (Al), gallium (Ga), orthe like can be used. In this case, boron (B) is introduced into theregion 2613 as the impurity element.

In this embodiment mode, the region 2612 is not doped with an impurityelement because a semiconductor substrate having n-type conductivity isused as the substrate 2600. However, an n well may be formed in theregion 2612 by introduction of an n-type impurity element. As an n-typeimpurity element, phosphorus (P), arsenic (As), or the like can be used.

When a semiconductor substrate having p-type conductivity is used, onthe other hand, the region 2612 may be doped with an n-type impurityelement to form an n well, whereas the region 2613 may be doped with noimpurity element.

Next, insulating films 2632 and 2634 are formed over the surfaces of theregions 2612 and 2613 in the substrate 2600, respectively (see FIG.15B).

For example, surfaces of the regions 2612 and 2613 provided in thesubstrate 2600 are oxidized by heat treatment, so that the insulatingfilms 2632 and 2634 of silicon oxide films can be formed. Alternatively,the insulating films 2632 and 2634 may each be formed to have a stackedstructure of a silicon oxide film and a film containing oxygen andnitrogen (a silicon oxynitride film) by the steps of forming a siliconoxide film by a thermal oxidation method and then nitriding the surfaceof the silicon oxide film by nitridation treatment.

Further alternatively, the insulating films 2632 and 2634 may be formedby plasma treatment as described above. For example, the insulatingfilms 2632 and 2634 can be formed with a silicon oxide (SiO_(x)) film ora silicon nitride (SiN_(x)) film which is obtained by application ofhigh-density plasma oxidation or high-density nitridation treatment tothe surfaces of the regions 2612 and 2613 provided in the substrate2600. In addition, after application of high-density plasma oxidationtreatment to the surfaces of the regions 2612 and 2613, high-densityplasma nitridation treatment may be conducted. In that case, siliconoxide films are formed on the surfaces of the regions 2612 and 2613 andthen silicon oxynitride films are formed on the silicon oxide films.Thus, the insulating films 2632 and 2634 are each formed to have astacked structure of the silicon oxide film and the silicon oxynitridefilm. In addition, silicon oxide films are formed on the surfaces of theregions 2612 and 2613 by a thermal oxidation method, and thenhigh-density plasma oxidation treatment or high-density plasmanitridation treatment may be performed to the silicon oxide films.

It is to be noted that the insulating films 2632 and 2634 formed overthe regions 2612 and 2613 of the substrate 2600 respectively function asthe gate insulating films of transistors which are completed later.

Next, a conductive film is formed so as to cover the insulating films2632 and 2634 which are formed over the regions 2612 and 2613 providedin the substrate 2600, respectively (see FIG. 15C). In this embodimentmode, an example is shown where the conductive film is formed bysequentially stacking conductive films 2636 and 2638. Needless to say,the conductive film may be formed to have a single layer or a stackedstructure of three or more layers.

As a material of the conductive films 2636 and 2638, an element selectedfrom tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo),aluminum (Al), copper (Cu), chromium (Cr), niobium (Nb), and the like,or an alloy material or a compound material containing such an elementas its main component can be used. Alternatively, a metal nitride filmobtained by nitridation of such an element can also be used.Furthermore, a semiconductor material typified by polycrystallinesilicon doped with an impurity element such as phosphorus can also beused.

In this case, a stacked structure is employed in which the conductivefilm 2636 is formed using tantalum nitride and the conductive film 2638is formed thereover using tungsten. Alternatively, it is also possibleto form the conductive film 2636 using a single-layer film or a stackedfilm of tantalum nitride, tungsten nitride, molybdenum nitride, and/ortitanium nitride and form the conductive film 2638 using a single-layerfilm or a stacked film of tungsten, tantalum, molybdenum, and/ortitanium.

Next, the stacked conductive films 2636 and 2638 are selectively removedby etching, so that the conductive films 2636 and 2638 remain above partof the regions 2612 and 2613 of the substrate 2600. Thus, conductivefilms 2640 and 2642 functioning as gate electrodes are formed (see FIG.16A). Here, surfaces of the regions 2612 and 2613 of the substrate 2600which do not overlap with the conductive films 2640 and 2642respectively are exposed.

Specifically, in the region 2612 of the substrate 2600, a part of theinsulating film 2632 formed below the conductive film 2640, which doesnot overlap with the conductive film 2640, is selectively removed, sothat the ends of the conductive film 2640 and the ends of the insulatingfilm 2632 are almost aligned with each other. In addition, in the region2613 of the substrate 2600, a part of the insulating film 2634 formedbelow the conductive film 2642, which does not overlap with theconductive film 2642, is selectively removed, so that the ends of theconductive film 2642 and the ends of the insulating film 2634 are almostaligned with each other.

In this case, the part of the insulating films or the like which do notoverlap with the conductive films 2640 and 2642 may be removed at thesame time as the formation of the conductive films 2640 and 2642.Alternatively, the part of the insulating films which do not overlapwith the conductive films 2640 and 2642 may be removed using resistmasks which are left after the formation of the conductive films 2640and 2642 or the conductive films 2640 and 2642 as masks.

Then, the regions 2612 and 2613 of the substrate 2600 are selectivelydoped with an impurity element (see FIG. 16B). At this time, the region2613 is selectively doped with an n-type impurity element at lowconcentration, using the conductive film 2642 as a mask, to form lowconcentration impurity regions 2650, whereas the region 2612 isselectively doped with a p-type impurity element at low concentration,using the conductive film 2640 as a mask, to form low concentrationimpurity regions 2648. As an n-type impurity element, phosphorus (P),arsenic (As), or the like can be used. As a p-type impurity element,boron (B), aluminum (Al), gallium (Ga), or the like can be used.

Next, sidewalls 2654 are formed so as to be in contact with the sidesurfaces of the conductive films 2640 and 2642. Specifically, thesidewalls are formed with a single layer or a stacked layer of aninsulating film such as a film containing an inorganic material such assilicon, silicon oxide, or silicon nitride, and/or a film containing anorganic material such as an organic resin by a plasma CVD method, asputtering method, or the like. Then, the insulating film is selectivelyetched by anisotropic etching mainly in the perpendicular direction, sothat the sidewalls 2654 can be formed so as to be in contact with theside surfaces of the conductive films 2640 and 2642. The sidewalls 2654are used as masks in doping for forming LDD (Lightly Doped Drain)regions. In addition, the sidewalls 2654 are formed to be in contactwith side surfaces of the insulating films formed below the conductivefilms 2640 and 2642.

Next, the regions 2612 and 2613 of the substrate 2600 are doped with animpurity element, using the sidewalls 2654 and the conductive films 2640and 2642 as masks, so that impurity regions which function as source anddrain regions are formed (see FIG. 16C). At this time, the region 2613of the substrate 2600 is doped with an n-type impurity element at highconcentration, using the sidewalls 2654 and the conductive film 2642 asmasks, whereas the region 2612 is doped with a p-type impurity elementat high concentration, using the sidewalls 2654 and the conductive film2640 as masks.

As a result, impurity regions 2658 which form source and drain regions,low concentration impurity regions 2660 which form LDD regions, and achannel formation region 2656 are formed in the region 2612 of thesubstrate 2600. Meanwhile, impurity regions 2664 which form source anddrain regions, low concentration impurity regions 2666 which form LDDregions, and a channel formation region 2662 are formed in the region2613 of the substrate 2600.

In this embodiment mode, the impurity elements are introduced under thecondition that parts of the regions 2612 and 2613 of the substrate 2600which do not overlap with the conductive films 2640 and 2642 areexposed. Accordingly, the channel formation regions 2656 and 2662 whichare formed in the regions 2612 and 2613 of the substrate 2600respectively can be formed in a self-aligned manner, due to theconductive films 2640 and 2642.

Next, an insulating film 2677 is formed so as to cover the insulatingfilms, the conductive films, and the like which are provided over theregions 2612 and 2613 of the substrate 2600, and opening portions 2678are formed in the insulating film 2677 (see FIG. 17A).

The insulating film 2677 can be formed with a single layer or a stackedlayer of an insulating film containing oxygen and/or nitrogen such assilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y) where x>y>0), or silicon nitride oxide (SiN_(x)O_(y) wherex>y>0); a film containing carbon such as DLC (Diamond-Like Carbon); anorganic material such as epoxy, polyimide, polyamide, polyvinyl phenol,benzocyclobutene, or acrylic; or a siloxane material such as a siloxaneresin, by a CVD method, a sputtering method, or the like. A siloxanematerial corresponds to a material having a bond of Si—O—Si. Siloxanehas a skeleton structure with the bond of silicon (Si) and oxygen (O).As a substituent of siloxane, an organic group containing at leasthydrogen (e.g., an alkyl group or aromatic hydrocarbon) is used. Inaddition, a fluoro group may be used as the substituent. Further, afluoro group and an organic group containing at least hydrogen may beused as the substituent.

Next, conductive films 2680 are formed in the opening portions 2678.Then, conductive films 2682 a to 2682 d and 2697 are selectively formedover the insulating film 2677 so as to be electrically connected to theconductive films 2680 (see FIG. 17B).

The conductive films 2680, 2682 a to 2682 d and 2697 are formed with asingle layer or a stacked layer of an element selected from aluminum(Al), tungsten (W), titanium (Ti), tantalum (Ta), molybdenum (Mo),nickel (Ni), platinum (Pt), copper (Cu), gold (Au), silver (Ag),manganese (Mn), neodymium (Nd), carbon (C), and silicon (Si), or analloy material or a compound material containing such an element as itsmain component by a CVD method, a sputtering method, or the like. Analloy material containing aluminum as its main component corresponds to,for example, a material which contains aluminum as its main componentand also contains nickel, or a material which contains aluminum as itsmain component and also contains nickel and one or both of carbon andsilicon. For example, each of the conductive films 2680, 2682 a to 2682d and 2697 is preferably formed to have a stacked structure of a barrierfilm, an aluminum-silicon (Al—Si) film, and a barrier film or a stackedstructure of a barrier film, an aluminum-silicon (Al—Si) film, atitanium nitride film, and a barrier film. It is to be noted that the“barrier film” corresponds to a thin film formed of titanium, titaniumnitride, molybdenum, or molybdenum nitride. Aluminum and aluminumsilicon are suitable materials for forming the conductive films 2680,2682 a to 2682 d and 2697 because they have low resistance values andare inexpensive. When barrier layers are provided as the top layer andthe bottom layer, generation of hillocks of aluminum or aluminum siliconcan be prevented. When a barrier film is formed of titanium which is anelement having a high reducing property, even if a thin natural oxidefilm is formed on the crystalline semiconductor film, the natural oxidefilm can be reduced, and a favorable contact between the conductivefilms 2680 and 2682 a to 2682 d, and the crystalline semiconductor filmcan be obtained. Here, the conductive film 2680 can be formed byselective growth of tungsten (W) by a CVD method.

Through the above steps, a p-channel transistor formed in the region2612 of the substrate 2600 and an n-channel transistor formed in theregion 2613 of the substrate 2600 can be obtained.

It is to be noted that the structure of transistors included in thesemiconductor device of the present invention is not limited to the oneshown in the drawings. For example, a transistor with an invertedstaggered structure, a FinFET structure, or the like can be used. AFinFET structure is preferable because it can suppress a short channeleffect which occurs along with reduction in transistor size.

The semiconductor device of the present invention is provided with thestorage capacitor by which power can be stored in the power supplycircuit of the CPU. As the storage capacitor, a capacitor such as anelectric double layer capacitor or a thin-film secondary battery ispreferably used. In this embodiment mode, a connection between thetransistor formed in this embodiment mode and a thin-film secondarybattery will be described.

In this embodiment mode, a secondary battery is stacked over theconductive film 2682 d connected to the transistor. The secondarybattery has a structure in which a current-collecting thin film, anegative electrode active material layer, a solid electrolyte layer, apositive electrode active material layer, and a current-collecting thinfilm are sequentially stacked (see FIG. 17B). Therefore, the material ofthe conductive film 2682 d which also has a function of thecurrent-collecting thin film of the secondary battery should have highadhesion to the negative electrode active material layer and also lowresistance. In particular, aluminum, copper, nickel, vanadium, or thelike is preferably used.

Subsequently, the structure of the thin-film secondary battery isdescribed. A negative electrode active material layer 2691 is formedover the conductive film 2682 d. In general, vanadium oxide (V₂O₅) orthe like is used. Next, a solid electrolyte layer 2692 is formed overthe negative electrode active material layer 2691. In general, lithiumphosphate (Li₃PO₄) or the like is used. Next, a positive electrodeactive material layer 2693 is formed over the solid electrolyte layer2692. In general, lithium manganate (LiMn₂O₄) or the like is used.Lithium cobaltate (LiCoO₂) or lithium nickel oxide (LiNiO₂) can also beused. Next, a current-collecting thin film 2694 to serve as an electrodeis formed over the positive electrode active material layer 2693. Thecurrent-collecting thin film 2694 should have high adhesion to thepositive electrode active material layer 2693 and also low resistance.For example, aluminum, copper, nickel, vanadium, or the like can beused.

Each of the above-described thin layers of the negative electrode activematerial layer 2691, the solid electrolyte layer 2692, the positiveelectrode active material layer 2693, and the current-collecting thinfilm 2694 may be formed by a sputtering technique or an evaporationtechnique. In addition, the thickness of each layer is preferably 0.1 to3 μm.

Next, an interlayer film 2696 is formed by application of a resin. Theinterlayer film 2696 is etched to form a contact hole. The interlayerfilm 2696 is not limited to a resin, and other films such as an oxidefilm formed by CVD method or the like may also be used; however, a resinis preferably used in terms of flatness. In addition, the contact holemay be formed without etching, but using a photosensitive resin. Next, awiring layer 2695 is formed over the interlayer film 2696 and isconnected to the conductive film 2697. Thus, an electrical connection ofthe thin-film secondary battery is secured.

With the above-described structure, the semiconductor device of thepresent invention can have a structure in which transistors are formedon a single crystal substrate and a thin-film secondary battery isformed thereover. Thus, by achieving thinning and reduction in size ofthe CPU, the semiconductor device of the present invention having a lotof flexibility in physical form can be provided.

The method for manufacturing the semiconductor device in this embodimentmode can be applied to any of the semiconductor devices in the otherembodiment modes.

(Embodiment Mode 7)

The semiconductor devices of the present invention can be applied tovarious electronic devices, specifically to driving of display portionsof electronic devices. Such electronic devices include cameras such asvideo cameras and digital cameras, goggle-type displays, navigationsystems, sound reproducing devices (such as car audio systems and audiocomponents), computers, game machines, portable information terminals(such as mobile computers, mobile phones, mobile game machines, andelectronic books), image reproducing devices provided with a recordingmedium (specifically, devices for reproducing content of a recordingmedium such as a digital versatile disc (DVD) and having alight-emitting device for displaying the reproduced image), and thelike.

FIG. 18A shows a light-emitting device, which includes a housing 6001, asupport base 6002, a display portion 6003, speaker portions 6004, avideo input terminal 6005, and the like. The display portion 6003 can bedriven by using the semiconductor device of the present invention. Notethat the light-emitting device includes various light-emitting devicesfor displaying information, for example, light-emitting devices forpersonal computers, television broadcast reception, and advertisement.By using the semiconductor device of the present invention, reduction inpower consumption can be achieved. Further, the semiconductor device ofthe present invention has a lot of flexibility in physical form, whichleads to reduction in size of the light-emitting device.

FIG. 18B shows a camera, which includes a main body 6101, a displayportion 6102, an image receiving portion 6103, operation keys 6104, anexternal connection port 6105, a shutter button 6106, and the like. Byusing the semiconductor device of the present invention, reduction inpower consumption can be achieved. Further, the semiconductor device ofthe present invention has a lot of flexibility in physical form, whichleads to reduction in size of the camera.

FIG. 18C shows a computer, which includes a main body 6201, a housing6202, a display portion 6203, a keyboard 6204, an external connectionport 6205, a pointing device 6206, and the like. By using thesemiconductor device of the present invention, reduction in powerconsumption can be achieved. Further, the semiconductor device of thepresent invention has a lot of flexibility in physical form, which leadsto reduction in size of the computer.

FIG. 18D shows a mobile computer, which includes a main body 6301, adisplay portion 6302, a switch 6303, operation keys 6304, an infraredport 6305, and the like. By using the semiconductor device of thepresent invention, reduction in power consumption can be achieved.Further, the semiconductor device of the present invention has a lot offlexibility in physical form, which leads to reduction in size of themobile computer.

FIG. 18E shows a portable image reproducing device having a recordingmedium (specifically, a DVD player), which includes a main body 6401, ahousing 6402, a display portion A 6403, a display portion B 6404, arecording medium (e.g. DVD) reading portion 6405, operation keys 6406, aspeaker portion 6407, and the like. The display portion A 6403 canmainly display image information and the display portion B 6404 canmainly display text information. By using the semiconductor device ofthe present invention, reduction in power consumption can be achieved.Further, the semiconductor device of the present invention has a lot offlexibility in physical form, which leads to reduction in size of theportable image reproducing device.

FIG. 18F shows a goggle-type display, which includes a main body 6501, adisplay portion 6502, and an arm portion 6503. By using thesemiconductor device of the present invention, reduction in powerconsumption can be achieved. Further, the semiconductor device of thepresent invention has a lot of flexibility in physical form, which leadsto reduction in size of the goggle-type display.

FIG. 18G shows a video camera, which includes a main body 6601, adisplay portion 6602, a housing 6603, an external connection port 6604,a remote controller receiving portion 6605, an image receiving portion6606, a battery 6607, an audio input portion 6608, operation keys 6609,and the like. By using the semiconductor device of the presentinvention, reduction in power consumption can be achieved. Further, thesemiconductor device of the present invention has a lot of flexibilityin physical form, which leads to reduction in size of the video camera.

FIG. 18H shows a mobile phone, which includes a main body 6701, ahousing 6702, a display portion 6703, an audio input portion 6704, anaudio output portion 6705, operation keys 6706, an external connectionportion 6707, an antenna 6708, and the like. By using the semiconductordevice of the present invention, reduction in power consumption can beachieved. Further, the semiconductor device of the present invention hasa lot of flexibility in physical form, which leads to reduction in sizeof the mobile phone.

As described above, the semiconductor device of the present inventioncan be applied to various electronic devices.

The structure of the semiconductor device and the method formanufacturing the semiconductor device in this embodiment mode can beapplied to any of the semiconductor devices in the other embodimentmodes.

This application is based on Japanese Patent Application serial No.2006-296650 filed in Japan Patent Office on Oct. 31, 2006, the entirecontents of which are hereby incorporated by reference.

1. A semiconductor device comprising: a first circuit; a second circuit;wherein the first circuit includes a first wireless circuit whichincludes a first coil and a modulation circuit, wherein the secondcircuit includes a second wireless circuit which includes a second coiland a demodulation circuit, wherein the first wireless circuit isconfigured to transmit data wirelessly, and wherein the second wirelesscircuit is configured to receive data based on the data transmitted fromthe first wireless circuit wirelessly.
 2. The semiconductor deviceaccording to claim 1, wherein the first wireless circuit is configuredto transmit data by a backscattering method.
 3. The semiconductor deviceaccording to claim 1, wherein each of the first circuit and the secondcircuit comprises a transistor.
 4. The semiconductor device according toclaim 3, wherein the transistor is a thin film transistor formed over aglass substrate or a plastic substrate.
 5. The semiconductor deviceaccording to claim 3, wherein the transistor is a transistor formed on asemiconductor substrate.
 6. The semiconductor device according to claim1, wherein the first circuit is a CPU, and the second circuit is arouter circuit.
 7. A semiconductor device comprising: a first circuit; asecond circuit; and a router circuit; wherein each of the first circuitand the second circuit includes a first wireless circuit which includesa first coil, a first demodulation circuit, a first modulation circuit,wherein the router circuit includes: a data processing circuit; and asecond wireless circuit which includes a second coil, a seconddemodulation circuit, and a second modulation circuit, wherein the firstwireless circuit and the second wireless circuit are configured totransmit and receive data between the first circuit or the secondcircuit and the router circuit wirelessly, and wherein the dataprocessing circuit is configured to process and store first data to betransmitted to or received from each of the first circuit and the secondcircuit.
 8. The semiconductor device according to claim 7, wherein thefirst wireless circuit is configured to transmit data to the secondwireless circuit by a backscattering method.
 9. The semiconductor deviceaccording to claim 7, further comprising: a thread control circuitconnected to the router circuit through a first bus; and an externaldevice controller connected to the router circuit through a second bus.10. The semiconductor device according to claim 7, wherein each of thefirst circuit and the second circuit comprises a transistor.
 11. Thesemiconductor device according to claim 10, wherein the transistor is athin film transistor formed over a glass substrate or a plasticsubstrate.
 12. The semiconductor device according to claim 10, whereinthe transistor is a transistor formed on a semiconductor substrate. 13.The semiconductor device according to claim 7, wherein the first circuitis a first CPU, and the second circuit is a second CPU.
 14. Thesemiconductor device according to claim 7, wherein the semiconductordevice is a multi-core semiconductor device.
 15. A semiconductor devicecomprising: a first circuit; a second circuit; and a router circuit;wherein each of the first circuit and the second circuit includes afirst wireless circuit which includes a first coil, a first demodulationcircuit, a first modulation circuit, and a power supply circuit, whereinthe power supply circuit is configured to generate a power supplyvoltage to be supplied to the first circuit or the second circuit from awireless signal received by the first coil, wherein the router circuitincludes: a data processing circuit; and a second wireless circuit whichincludes a second coil, a second demodulation circuit, and a secondmodulation circuit, wherein the first wireless circuit and the secondwireless circuit are configured to transmit and receive data between thefirst circuit or the second circuit and the router circuit wirelessly,and wherein the data processing circuit is configured to process andstore first data to be transmitted to or received from each of the firstcircuit and the second circuit.
 16. The semiconductor device accordingto claim 15, wherein the first wireless circuit is configured totransmit data to the second wireless circuit by a backscattering method.17. The semiconductor device according to claim 15, further comprising:a thread control circuit connected to the router circuit through a firstbus; and an external device controller connected to the router circuitthrough a second bus.
 18. The semiconductor device according to claim15, wherein each of the first circuit and the second circuit comprises atransistor.
 19. The semiconductor device according to claim 18, whereinthe transistor is a thin film transistor formed over a glass substrateor a plastic substrate.
 20. The semiconductor device according to claim18, wherein the transistor is a transistor formed on a semiconductorsubstrate.
 21. The semiconductor device according to claim 15, whereinthe first circuit is a first CPU, and the second circuit is a secondCPU.
 22. The semiconductor device according to claim 15, wherein thesemiconductor device is a multi-core semiconductor device.